Wednesday, May 26, 2010

Genetics, Ethics, and Self Discovery

Here is an interesting posting by Ursula Goodenough on the NPR 13.7 blog:
In one of his lectures, Stephen J. Gould wondered aloud what it would be like if the Australopithicus genus and the other Homo species had not gone extinct and were instead still with us today. He didn’t offer an answer. He just noted, and I agree, that it was an interesting question to think about.

Two news items in the past few weeks converge on Gould’s question. The first is the announcement from Craig Venter’s biotech company that they have artificially synthesized a functional bacterial chromosome. The second is the announcement here and here from Svante Pääbo’s lab that they have produced a first draft of the Homo neanderthalensis (Neanderthal) genome sequence based on DNA fragments extracted from fossil bones.

Hence it is now formally feasible, albeit not yet remotely practicable, to synthesize artificial Neanderthal chromosomes, insert copies into enucleated human eggs, and recruit volunteers to give birth to a Homo species that has been extinct for 30,000 years.

Now to put this scenario in perspective, let’s imagine a different proposal. Scientists have obtained DNA from recovered bones of the dodo, (Raphus cucullatus), a bird that has been extinct since the mid-17th century. Hence it is also formally feasible to sequence the dodo genome, insert artificial copies into enucleated pigeon eggs, and hatch out bona fide Rapus cucullatus.

My hunch is that readers might have a vague “that’d-be-kinda-cool” response to the dodo experiment, but that responses to the Neanderthal experiment would be pretty intense. So what’s the difference? Well, obviously, the difference is that the Neanderthals are our sister species, so ethical issues arise. I’ll return to that shortly.

Meanwhile, here’s the real mind-blower from the Pääbo lab’s report: They estimate that most human genomes contain 1-4% Neanderthal-derived DNA sequences. This could only be the case if H. sapiens and H. neanderthalenis had interbred, which apparently occurred, minimally, during two independent historical periods, one ~60,000 years ago in the eastern Mediterranean and the other ~45,000 years ago in east Asia.

The Neanderthal sequences are detected in present-day persons of European and Asian descent but not in present-day persons of African descent, which is not surprising given the fossil record: H.sapiens and H. neanderthalensis lived in overlapping regions of Europe and the Middle East for many thousands of years, whereas Neanderthal remains have yet to be found in Africa.
Taking this last paragraph, Goodenough makes the obvious conclusion:
It perhaps goes without saying that there’ a piquant irony here. 1) Non-African cultures have a shameful history of considering persons of African origin to be “savages.” 2) The term “neanderthal” is used to denote a brutish savage. And now we learn…
This is funny. And, this is an excellent antidote to those who want to classify others, especially on insufficient knowledge. Racism is a prejudice for this very reason.

I for one would like to see as many species "resurrected" as possible. I think we can solve the moral & ethical issues as needed.

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